System for testing closed receptacles for leaks



@ct, w, H953 P. PEARLMAN SYSTEM FOR TESTING CLOSED RECEPTACLES FOR LEAKSFiled 'May 21, 1948 INVENTOR. PHIL/P 7m MzM Patented Oct. 30, 1951UNITED STATES FICEZv 2,573,059 I SYSTEM FOR TESTING CLQSED-RECEP-TACLESFORLEKKS H Philip Pearlman, Chicago, Ill., assignortolI-lnitedStates Barrel & Drum Corponation,.New York, Y., a; corporation ofDelaware This invention relates to systems for testing, closedreceptacles. More particularlh the iiiventi'onpertain to systems whichare character.- izedby their. rapidity inhdetermining the presence ofleaks.

It is common practice to reuse receptaclessuch. as, drums and tank carscommercially em loyee tovcarry. fluids. Depending upon the nature ortheir use, these receptacles have tor be. cleaned" after a single orseveral refills. Sometimes the cleaning operation. quite severe, forii'lstarice, after handlingroil, driimshaye. to be sand'hlas'teli;vwashed andlchainedlv It hasrbeen feund'that receptacles prepared forreusein this manner'often develop leaks. Inasmuch. as'ifsuch'receptacles are refilledl their contents will he. lost, it isiniperative to. detect, the presence. ofw leaks before reuse. Where.the. defects 7 are visible, e. g..l'arge crackano difficultyistencountered'in weeding. oiit. the. had receptacles.- However, on.many occasions the. defects consist only ofi'ahairli'ne craclil orpinhole which. a.fvisual. inspection cannot" locate.

It is an object of the. present invention to provide .a system.whichrislcapable of fvery rapidly detecting the. presence of. such:tiny, defects in receptacles of the character. describedl.

It ,is a. further object of thelinventionto pro-,- vide a. leakdetecting system which issimple to operate, will not getout ofl ordereasily, and. comparatively inexpensive.

Iii general, thelse'veral objectsioflthe invention are. achievedb'y,flowing, air from a, high ressure source, into. the. receptecl too betested; cutting off thefiow ofcompresse'd air when the pressure in" thereceptacle has reached. at. predetermined value less than that of, the.source, and."theie-' after observing the pressure. inth'e receptacle todetermine whether the same is maintained? constant; Preferably,.v meansi'sincludedfto detect: and "signal; visually, or" audibly whenthepressurei in the receptacle has dropped'a'sinallpredeter, minedamount. Thelsystem desirably includes a mechanism which automaticallycuts" ofifi'ow of compressed air to therecept'acle at the predeterminedpressure; whereby'the'pressurein the receptacle can be builtup veryrapidly and cut" off with substantial accuracy; This" enablesthe systemito" operate speedily inasmuch as the re ceptacle not only i's"fi1led"quickly; butia" veryf small drop in pressurespeedily'cam be" ascer=-tained;

Other objects of i my invention will inpart be obvious and" in part will*be"pointed-'outherein after:

My invention accordingly consists the f'a tures of construction,combinationsof elements= and" arrangements of partswhich will heexemplifiecl in the" construction hereinafter 'describedi and of whichthe scope-"of applicationwillbe' indicated in'the appendd lclaimss r theaccompanying drawings; which shown one =of the" various==possible'emb'odimeiitsof my invention,

" suitable container in which air rriai'ntai incl: pressure b'yconventional means suchlas an eieetfi'cany drivencompressor (notShovvrflh The ressure of the air in the t ank is maintainedsubstantially abbve-tl'ie testing pressure, for example, if a testingpressure 'Of 8' pounds p. S, ii

(per square inch) is employed;vsatisfactdfiisuliii are obtainedwhr'e theair pressureifi the tank" is 5011551 Ii. i'." The compressed air is ledfrom the tank the testing ap aratus lfthrough a conduit l4.seiasppa'mtiis includes an" electrically. controlled valve l6 of thenormally clbs'editype to wriose' inletitiie condiiit I8 is connected.Therotata file. valve element I 8 has a passageway normallyaligriedW'ith the'po'rts'ii'rthe valvese'at'; Secured to said elementis. a handle 20 tiirougnwiitse movement the passageway or the valveelementcan be broughtinto registrywith the v'a1v'e' ports, The handleis, urged'byf'a'eompreSsiohspriiTgT 22" into a position corresponding tothe closed poSi tion of the" valve" element; An armature 23op'erativel'y attached to the handle";v said arma ture' being"associated with a" solenoid" 23' so tfia't" upon energization' of? the--solenoid, the valve Willi be quickly opened; The spring 22 is strongenough to effect" quickclosing ofthe valve upon deenergizationof thesolenoid; a The "apparatus 12 also includes a pressure" re? sponsivemechanism 26: B'y'wa'yofexample; this mechanism maWbea type o'f controlwhich in itself is-conventional and is'characterized bythe provision ofa" painof'normallyclosed contacts" which are opened when a; controllingressure rises above a predetermined' value: Themecha nismig suclr thatthe contacts will-"reclose thecontrolling pressure drops a" certainamoiint} the drop" for conve-niencehereinafterbein'g' re ferredtd asthe- "difierentiafpressure drop: De t e" pfes'sure -at which thecontacts opeir is regulata-ble inorder=that apressuremay' be: set

' which suitable-to the receptacle: being tested-f- In-addi-tion', thedifierential 'pressure also may be regulatablee r It will beunderstoo'dby tlio'se'slilldinih art thatvarious types -o'f con'structions' memployed to effect 'the foregoingFoperationi- Hbvt ever; for the-purposeof-- illnstration, one such construction is-shown 2. Franchisee-cre itwill'he seen' that the mechanism 2 6 ludes' an operating lever- 28 whichturns abolit a .Sylplion bellowsiincreases ithe operatingwlever2 8 willrock in a counterclockwise direction as viewed pivot 3m one. end oi the1ever is connectea to or bears;

from Fig. 2. The other end of the operating lever is attached to thelower end of a tension spring 36 whose upper end is connected to a screw38 threaded in a tapped opening 46 in a stationary portion of themechanism 26, whereby turning the screw will vary the pressure opposingexpansion of the Sylphon bellows.

The operating lever 28 has mounted thereon a bracket 42 which carries apin 44'slidable in a slot 46 of a bell crank lever 48. Said lever ispivoted at 56 and mounts a fixture 52 which supports a conventionalmercury switch 54'. This switch, as is usual, constitutes an envelope 56at one'end of which'a pair of electrodes 58 are disposed within theenvelope in proximity to one another. A pool of mercury 66 also islocated within the envelope, said pool being sufliciently large tobridge the space between the two electrodes when the tube is in theproper position, such for instance as is shown in Fig. 2. When theSylphon bellows expands, it will, through the bracket 42, pin 44 andslot 46, rock the bell crank lever 48 in a counterclockwise direction asviewed from'Fig. 2. This motion will raise the end of the "mercuryswitch containing the electrodes. If the switch is rotated'sufficiently, the mercury' will leave the two electrodes and flow tothe opposite end of the tube, thus opening the circuit controlled by themercury switch. Such action will take place at a predetermined angularposition of the envelope 56.

The mechanism 26 also includes another tension spring 62 connected atone end to a lever 64, and at its opposite end to a screw 66 threadedthrough a tapped opening 68 in a stationary portion of the mechanism 26.The lever 64 turns about a pivot 16, being urged in a counterclockwisedirection by the spring 62 to abut against the tip of a screw I2threadedly received in a'stationary portion of the mechanism' 26,whereby the opposite end of the lever 64 may be disposed in apredetermined position when the lever 64 is idle. Said opposite end ofthe lever 64 has an abutment member 14 located beneath the end of theoperating lever 28 associated with the tension spring 36. The spacingbetween said abutment member and the operating leveris controlled by thescrew I2.

'Said abutment member is so .located with respect to the operating leverby adjustment of the screw I2 that the operating lever will contact theabutment member just before the mercury switch 54 reaches the positionat which the pool of mercury flows away from the electrodes. With thisarrangement, a rising pressure within the Sylphon bellows will cause theoperating lever to tilt against the pressure of the spring 36 until theswitch 54 is almost ready to open. Further tilting of the operatinglever by increasing pressure in the bellows is opposed by the combinedforces of the springs 38, 62 so that to open the switch 54, a pressureequivalent to the combined forces of the two springs is necessary.However, when the pressure falls, the switch will reclose when theoperating lever disengages the abutment member. In other words,thepressure required to open the switch is governed by combined force -ofboth springs, but the pressure at which the switch recloses is governedby the spring 36 alone. Accordingly, the spring 36 is sometimes referredto as the pressure adjusting" spring, whereas the spring 62 is referredto as the differential adjusting spring. If the spring 36 is set to 6pounds p. s. i., and the differential spring is set to 2 4 pounds p. s.i., the mercury switch will open when there is 8 pounds p. s. i.pressure in the Sylphon bellows, and will reclose when the pressure inthe bellows drops to 6 pounds p. s. i.

The apparatus l2 includes a second pressure responsive mechanism "I4.This mechanism likewise may be a controller having the same type ofinternal construction as the mechanism 26. However, the differentialspring on the second pressure responsive mechanism preferably is lighterthan that of the first.

In addition to the two pressure responsive mechanisms and theelectrically controlled valve, said apparatus I2 includes a normallyopen single-pole single-throw hand controlled electric switch "I6, anelectrically controlled signalling means, e. g. an incandescent electricbulb I8, an

air pressure gauge 86 and a double pole, single throw line electricswitch 82. All of the parts of the apparatus I2 thus far described maybe mounted on a board or panel 84 represented by dotted'lines in Fig. 1.

lower end which is sufficiently small easily to enter an aperture 92 ina receptacle 94 to be tested. Surrounding the pipe and resting on theflange 96 is a sleeve 94 of an elastomeric substance such as rubberWhose outer diameter likewise is sumciently small, when in relaxedcondition, to enter the aperture in the receptacle. Slidably mounted onthe pipe above the sleeve 94 is a collar 96 having an outwardlyextending flange 98 at its lower end. This collar forms a follower for acam 98 which is secured to a handle I66 pivotally mounted on the pipe88.

The handle can be swung between two positions in one of which the flange'98 is relatively remote from the flange 96 and in the other of whichthe 1 flange 98 is closer to the flange 96. In the firstnamed positionof the cam the two flanges are spaced apart a distance substantiallyequal to the length of the elastomeric tube 94. In the other position ofthe cam the flanges compress the sleeve causing it to distend andfrictionally engage the aperture 94. The pipe 88 terminates at its upperend in two hose fittings which receive conduits I62, I64. The conduitI62 runs from the pipe 88 to the outlet of the valve I6.

* The conduit I64 is connected to the Sylphon belone of the normallyclosed contacts lows of both the pressure responsive mechanisms 26, 14.Said conduit I64 also is attached to the inlet of the pressure gauge 86.

Leads I66 connect a source of electrical energy I68 to the stationarycontacts of the line switch 82. One of the movable contacts of saidswitch is connected by a lead I I6 to a contact of thehand switch I6,the other contact of said hand switch being connected by a lead II2 to vof the first pressure responsive mechanism 26. The other contact of saidmechanism is connected by a lead II4 to the solenoid 24 of theelectrically controlled valve I6. A lead I I6 runs from the otherterminal of the solenoid to the other movable to give a combinedpressure equivalent to 8 pounds p. s. i., e. g. the pressure adjustingspring is set at 6 pounds p. s. i. and the differential ada thma Jus nespr n is set at pouudsp- If n w; with th uns 86 fi mt i e openin th reptacle 94 (all t er ope in s b ing c os the line swit h 82 and t e handsw t h 16 are closed, potential will be applied to the solenoid 24causing the valve [6 to open and allow air under pressure to flow fromthe tank into the receptacle. As air flows into the receptacle, theincreasing pressure therein will be registered on the gauge 89 and willbe applied to the Sylphon bellows of the first pressure responsivemechanism 26. When the pressure in the receptacle 9d reaches 8 pounds p.s. i., it will open the normally closed contacts of the first pressureresponsive mechanism. This will break the circuit energizing thesolenoid 24 and allow the spring 22 to close the valve Hi. In practice,I have found that the pressure responsive mechanism will cut off air invery exact response to the pressure of the air within the receptacle sothat when the valve I6 is closed, the pressure in the receptacle will bevery close to, i. e., within two ounces or less of the pre-set cut offpressure. Moreover, the pressure in the receptacle will not vary fromreceptacle to receptacle being tested even with the usual variations inthe pressure maintained in the tank due to the compressor cutting in andout.

The second pressure responsive mechanism 14 is connected in circuit asfollows: A lead I I8 runs from one of the movable contacts of the. lineswitch 82 to a normally closed contact of said mechanism 74. From theother contact of said mechanism a lead E29 runs to one side of thesignalling means 18. The other side of the signalling means is connectedby a lead 122 to the other movable contact of the line switch.

The cut-01f pressure of the pressure responsive mechanism 14 is set asclose as possible to but below the cut-01f of the mechanism 26. Thus, ifthe mechanism 26, in the example given above, cuts off at 8 pounds p. s.i., the mechanism i4 is set to cut off at approximately 7 pounds, 14:ounces p. s. i. This may be done, for example by having the pressureadjusting spring in the mechanism it set to 6 pounds, ounces p. s. i.and the diiferential adjusting spring set to 9 ounces. With thisarrangement, when the air in the receptacle 9 being tested reaches apressure sufficiently high to open the normally closed contacts of thefirst pressure responsive mechanism 2 3, it will, just prior to openingsaid contacts, open the normally closed contacts of the second pressureresponsive mechanism 14. Therefore, the light '18 which is energized atthe time the line switch 82 is closed will be deenergized just prior toattainment of cut-out pressure.

The receptacle fills up very quickly so that a few seconds after theline switch and hand switch are closed, the light will go out.Subsequently, if there is a leak in the receptacle, the pressure in theconduit I04 will drop.

Because I am able to obtain the predetermined cut-out pressure with ahigh degree of accuracy, the cut-in or diiferential pressure of thepressure responsive mechanism M can be-"sttvery close to said cut-outpressure, in the instant case. 9 ounces, p. s. i., whereby the pressureresponsive mechanism M is very sensitive to a drop in pressure. Even acomparatively tiny leak in the receptacle 94 will, at a cut-out pressureof '8 pounds p. s. i., drop within a comparatively short time to thecut-in pressure of the pressure responsive mechanism 14. I have foundthat if the cut-out pressure is 8 pounds p. s. i., any leak in a drumwhich would render. it unfitfor use will cause a pressure drop. of 9 once pi. o e reached withinless thanfifteen seconds. when the pres.-sure. in the receptacle drops to. th pred ermined cut-in pressure; theli ht 18. will. e. reener izedlherefore, to test a receptacle. an.operator simply puts the. bung 85. in. place, the witch 8.2 having beenpreviously. closed, and clos s the switch 16. He. then Watches the light7.8.. Within a few seconds after. closin the switch 15., the. light.will. go out. If the li ht does not go. on again within about 15seconds, he knows that the receptacle. bein tested is satisfactory.

If a. leaky receptacle is left connected with the testingapp'aratusafter the light goes on again, the pressure will drop back to the cut-inpressure of the first pressure responsive. mechanism 26 and will reopenthe valve [6. However, such. an operation is not necessary to. thepractice of my. invention, and, therefore, if. desired, the differentialpressure. function of said first pressure. responsive' mechanism may beomitted, providing, how.- ever, that said mechanism is not soconstructed as to cut-in just below its cut-out pressure.

The gauge 89. is employed for checking purposes.

Itthus will be seen that I have provided a system for testing closedreceptacles which achieves the several objects of my invention and iswell adapted to meet. the conditions of practical use.

As. various. possible embodiments may be made of this. invention, and asvarious changes might be made in the embodiment above set forth, it isto be understood that all matter herein described or shown in the.accompanying drawings is to be interpreted as illustrative. and not in"a limiting sense. 1 I

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

1. An apparatus for testing closed receptacles, which apparatus isadapted to be used with a source ofcompressed air and a source ofelectric energy, said apparatus comprising a normally closedelectrically controlled valve, a quick at} tachable and detachablefluid-passing bung adapted'to be attached to'and detached from areceptacle to be tested, conduit means connecting said source ofcompressed air to the inlet of saidvalve, conduitmeans connecting theoutlet of said valve't'o said bung, a switch, means controlled by theswitch and responsive to the pressure within the receptacle being testedto connect said source ofelectric' energy to said valve and thereby openthe same when the switch is closed and the re c'eptacle is being filledwith compressed air so long as the pressure in said receptacle is belowa predetermined pressure less than the pressure of the source ofcompressed air and to disconnect said source of electric energy fromsaid valve andthereby close the same when the air pressure of thereceptacle. being filled is at said predetermined pr'essureQwhereby saidreceptacle will be filled with air. at a predetermined pressure less.than and independent of the pressure of. the source ocompressed air, anelectrically. con:- trolled. signalling means, and means. responsive.to. the pressure of the air. within the receptacle toconnect. thesignalling means to said source of. electric, energy and thereby. renderthe same effective when the. pressure of the air inside the. receptacle.being. tested falls at predetermined amount .below the predetermined:pressure.

2. An apparatus. for testing. closed receptacles, which apparatus is.adapted to. be used with a source of compressed air and a source ofelectric energy, said apparatus comprising a normally closedelectrically controlled valve, a quick attachable and detachablefluid-passing bung adapted to be attached to and detached from areceptacle to be tested, conduit means connecting said source ofcompressed air to the inlet of said valve, conduit means connecting theoutlet of said valve to said bung, a switch, pressure responsive meansconnected to said bung, said pressure responsive means being controlledby said switch and controlling the supply of electric energy to saidvalve in such manner as to open said valve and maintain the same openwhen the switch is closed and the receptacle is being filled with air solong as the pressure in the receptacle is below a predetermined pressureless than the pressure of the source of compressed air and to close saidvalve when the air pressure in the receptacle being filled is at saidpredetermined pressure, whereby said receptacle will be filled with airat a predetermined pressure less than and independent of the pressure ofthe source of compressed air, an electrically controlled signallingmeans, and pressure responsive means connected to said bungand'controlling the supply of electric energy from the source ofelectric energy to said signalling means, the pressure at which saidsecond pressure responsive means is operative to energize the signallingmeans being less than the pressure at which the first pressureresponsive means is operative to cut-ofi flow of air at the electricallycontrolled valve.

3. An apparatus for testing closed receptacles, which apparatus isadapted to be used with a source of compressed air and a source ofelectric energy, said apparatus comprising a normally closedelectrically controlled valve, 9, quick attachable and detachablefluid-passing bung adapted to be attached to and detached from areceptacle to be tested, conduit means connecting said source ofcompressed air to the inlet of said valve, conduit means connecting theoutlet of said valve to said bung, a normally closed pair of electriccontacts, means connecting said pair of contacts in series with saidvalve, a switch in series with said pair of contacts and said source ofelectric energy, a pressure responsive means operatively connected tosaid pair of contacts and arranged to open said contacts when thepressure applied thereto reaches a predetermined value, conduit meansconnecting said bung to said pressure responsive means whereby when saidbung is connected to a receptacle to be tested and said switch isclosed, said receptacle will be filled with air at a predeterminedpressure less than and independent of the pressure of the source ofcompressed air, a signalling means, a second pair of contacts, means toconnect said second pair of contacts in series with said source ofelectric energy and said signalling means, pressure responsive meansoperatively connected to said second pair of contacts, said secondpressure responsive means being constructed to operate said second pairof contacts and render the signalling means efiective at a predeterminedpressure less than that of the predetermined pressure at which saidfirst pair of contacts are opened, and conduit means connecting saidsecond pressure responsive means to said bung whereby said second pairof contacts automatically will be actuated to render said signallingmeans effective if a leak is present in said receptacle.

I 4. An apparatus as set forth in claim 3 whereinmeans'is provided forregulating the predetermined pressure at which the second-named pressureresponsive means operates the secondnamed pair of contacts to render thesignalling means effective.

5. An apparatus as set forth in claim 3 wherein means is provided toregulate the predetermined value of the pressure at which the firstnamedpressure responsive means opens the firstnamed pair of contacts. 6. Anapparatus as set forth in claim 3 wherein means is provided forregulating the predetermined pressure at which the second-named pressureresponsive means operates the secondnamed pair of contacts to render thesignalling means efiective, and wherein means is provided to regulatethe predetermined value of the pressure at which the first-namedpressure responsive means opens the first-named pair of contacts.

7. An apparatus for testing closed receptacles, which apparatus isadapted to be used with a source of compressed air and a source ofelectric energy, said apparatus comprising a normally closedelectrically controlled valve, a quick attachable and detachablefluid-passing bung adapted to be attached to and detached from areceptacle to be tested, conduit means connecting said source ofcompressed air to the inlet of said valve, conduit means connecting theoutlet of said valve to said bung, a normally closed pair of electriccontacts, means connecting said pair of contacts in series with saidvalve, a switch in series with said pair of contacts and said source ofelectric energy, a pressure responsive means operatively connected tosaid pair of contacts and arranged to open said contacts when thepressure applied thereto reaches a predetermined value, conduit meansconnecting said bung to said pressure responsive means whereby when saidbung is connected to a receptacle to be tested and said switch isclosed, said receptacle will be filled with air at a predeterminedpressure less than and independent of the pressure of the source ofcompressed air, a signalling means, a second pair of normally closedcontacts, means to connect said second pair of contacts in series withsaid sources of electric energy and said signalling means, a pressureresponsive means operatively connected to said second pair of contacts,said second pressure responsive means being constructed to open saidsecond pair of contacts at a pressure less than that of thepredetermined pressure at which said first pair of contacts are openedand to reclose said second pair of contacts at a predetermined pressurebelow the predetermined pressure at which said first pair of contactsare opened, and conduit means to said bung whereby.

said second pair of contacts automatically will be actuated to rendersaid signalling means efiective by reclosing said second pair ofcontacts if a leak is present in said receptacle.

PHILIP. PEARLMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,297,113 Domenico Mar. 11, 19191,350,358 Cone Aug. 24, 1920 1,884,942 Widell Oct. 25, 1932 1,933,322Fagan Oct. 31, 1933 2,472,973 Hoffman et al June 14, 1949.,

